Cardiff snatched an injury-time equaliser.
Dorrans told Sky Sports: "It's very disappointing. It feels like a defeat - everyone is very unhappy because it would have been a massive three points for us.
"Sadly, it wasn't to be and we conceded a silly goal near the end but we have to stick together and move on to the next game (at Norwich). Hopefully we can pick up points then.
"The first half was probably the best we've played all season - we could have been three, four or even five up. It wasn't to be and we move on."